Vaccines can be roughly divided into two categories, “inactivated vaccines” and “non-inactivated vaccines”. For pregnant women, inactivated ones can be given, while attenuated or live vaccines cannot be given. Inactivated vaccines mean that the microorganisms in the vaccine have been killed by chemical or physical means, but are sufficient to give the body immunity. Vaccines such as tetanus, for example, can be used during pregnancy. Attenuated or live-attenuated vaccines, which are made of microorganisms with weakened pathogenic power, are the only ones that keep “alive” enough for the body to develop immunity. Measles vaccine and rubella vaccine are among such vaccines and are prohibited during pregnancy. I. These vaccines are not prohibited during pregnancy but recommended instead. During pregnancy, some viral or bacterial infections can have an impact on the development of the fetus and even threaten the life of the baby. For this reason, the following two vaccines are recommended. 1.Influenza vaccine Influenza vaccine mainly prevents infection with certain sub-strains of influenza virus in the season. If you are pregnant during the high influenza season, such as between November and March, it is recommended to get a flu vaccination shot regardless of whether the pregnancy falls into early, middle or late pregnancy, as it is mostly an inactivated vaccine that is safe and effective. However, it is important to note that the flu vaccine inhaled via the nose is a live vaccine and should be avoided according to the principles we just mentioned. If you are preparing for pregnancy during the high season of influenza and are not pregnant, the two flu vaccines mentioned above can be used during the preparation stage. 2.Diphtheria vaccine Regardless of when the vaccine was given before pregnancy, it is recommended to be given again during pregnancy. This vaccine can prevent diphtheria, acellular pertussis and tetanus. The best time to get vaccinated is between 27 and 36 weeks of pregnancy, so that both the baby and the mother can be protected. What are the vaccines that are contraindicated during pregnancy? The following vaccines are all live attenuated virus vaccines and are contraindicated during pregnancy: measles, rubella, mumps, varicella, BCG, etc. In addition, there is no clear evidence that human papillomavirus (HPV) vaccination during pregnancy is harmful to the fetus. However, because the research data are not sufficient, it is recommended that vaccination not be continued if pregnancy is detected. However, if you have already received the vaccine during previous pregnancies, there is no need to terminate the pregnancy. III. Can these vaccines be administered during pregnancy? 1. These vaccines, which can be prophylactically administered to pregnant women exposed to high risk Hepatitis B vaccine is a recombinant vaccine and can be administered if exposed to high risk. Hepatitis A vaccine is an inactivated virus vaccine and can be administered if there is a high risk of exposure. Pneumococcal vaccine is an inactivated bacterial vaccine, the indication for vaccination does not change due to pregnancy, and the vaccine is only used in high-risk groups. 2. These vaccines can be given to pregnant women, but are not recommended in routine situations Meningococcal vaccine is an inactivated bacterial vaccine, the indications for vaccination do not change due to pregnancy, and vaccination during pregnancy is recommended in case of an outbreak. Typhoid vaccine is an inactivated bacterial vaccine and is not recommended during pregnancy unless there is close, ongoing exposure or travel to an endemic area. 3. These vaccines, which can be given in case of an outbreak during pregnancy Rabies vaccine inactivated virus vaccine for prevention after being bitten or scratched by a dog or other animal, can be given during pregnancy. Tetanus toxoid is used for the prevention of wounds after contamination, and can be inoculated during pregnancy. 4. In addition, there is a class of biological agents that cannot be called vaccines but can also be used for disease prevention Rabies immunoglobulin is a specific immunoglobulin used for post-exposure prophylaxis and can be given during pregnancy. It is used in conjunction with rabies vaccine. Tetanus immunoglobulin is a specific immunoglobulin for post-exposure prophylaxis and can be given during pregnancy. It is used in combination with tetanus toxoid. Varicella immunoglobulin is a specific immunoglobulin and can be considered for vaccination in healthy pregnant women exposed to varicella to protect the mother rather than to prevent congenital infection in the fetus. IV. What vaccines can be given to breastfeeding women? Any vaccine can be administered during breastfeeding. Breastfeeding will not affect vaccines and vaccines will not affect breast milk. V. What do women who are preparing for pregnancy need to pay attention to when receiving vaccines? If the vaccine given to a woman during pregnancy preparation is a vaccine that is contraindicated during pregnancy, then it is recommended that the vaccine be given one month before pregnancy. Finally, it is emphasized that there is no evidence that vaccination during pregnancy can lead to fetal health damage, and even if a live virus vaccine is contraindicated, the effect on the fetus is unknown; therefore, it is not recommended to easily terminate a pregnancy because of such vaccination. Of course, if you already know you are pregnant, it is safe to avoid vaccinations that are currently contraindicated during pregnancy.